The present invention relates to a case hardening steel with a minimum of grain boundary oxidation, which is suitable for use in the manufacture of mechanical components with high demands on fatigue resistance and wear resistance.
In, for example, gear transmissions, the movable parts are exposed to heavy stresses. In order to obtain a stronger material, the steel is alloyed. It has been found that among other alloying elements, Si, Mn and Cr are deleterious in increasing the depth of grain boundary oxidation. The content of those substances that can be increased first-hand in order to improve this effect are Ni and Mo, but they are very expensive.